Hybrid laser-arc welding combines the speed and productivity of laser welding with the robustness of arc welding. Although the principle of the technique has been known for many years, only relatively recently have industrial users started to investigate the process in earnest.
Laser welding now has many industrial applications, but one of the major limitations to the full acceptance and implementation of the process is its requirement for good joint fit up. The ability to cope with variable fit up can be vastly improved by combining the laser with a suitable arc welding process which also provides further benefits in terms of increased productivity and weld quality.
Recent work carried out at TWI, including in the Core Research programme, has demonstrated that both CO 2 and Nd:YAG lasers can be combined with MIG/MAG, plasma and TIG arc processes in the same welding pool to improve laser welding performance.
Currently TWI has a number of initiatives in this area for a range of different industrial sectors, one of which is the upstream oil and gas industry. The potential benefits of hybrid laser GMAW welding for welding pipelines have been highlighted and two large projects are in progress. The first is a project for BP using MIG/MAG welding in conjunction with the very high power 10kW Nd:YAG laser beam and the second is a group sponsored project (YAGPIPE).
Specific hybrid laser/arc procedures are also being developed at TWI for, amongst others, shipbuilding and aerospace. Also, a new group sponsored project Hybrid laser-arc processing for improved productivity and quality is about to start which will have relevance to all industrial sectors including automotive and construction. This project will be carried out as a collaboration with the French Institute de Soudure and is being formed with the joint objectives of evaluating the industrial welding performance of alternative hybrid laser-arc systems and comparing these processes with existing laser and arc systems. Specifically, the project will define the tolerance limits on an industrial scale for welding with a hybrid combination of Nd:YAG and CO 2 lasers, together with the plasma arc, TIG and MIG/MAG processes. Parameters to be studied will include speed, joint tolerance, weld quality and joint properties, for a range of materials including both steel and aluminium.
For further information on this Group Sponsored Project please contact the TWI Project Leader David Taylor.